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Diffstat (limited to 'services/sync/modules/engines/addons.sys.mjs')
| -rw-r--r-- | services/sync/modules/engines/addons.sys.mjs | 818 |
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diff --git a/services/sync/modules/engines/addons.sys.mjs b/services/sync/modules/engines/addons.sys.mjs new file mode 100644 index 0000000000..782d23239e --- /dev/null +++ b/services/sync/modules/engines/addons.sys.mjs @@ -0,0 +1,818 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* + * This file defines the add-on sync functionality. + * + * There are currently a number of known limitations: + * - We only sync XPI extensions and themes available from addons.mozilla.org. + * We hope to expand support for other add-ons eventually. + * - We only attempt syncing of add-ons between applications of the same type. + * This means add-ons will not synchronize between Firefox desktop and + * Firefox mobile, for example. This is because of significant add-on + * incompatibility between application types. + * + * Add-on records exist for each known {add-on, app-id} pair in the Sync client + * set. Each record has a randomly chosen GUID. The records then contain + * basic metadata about the add-on. + * + * We currently synchronize: + * + * - Installations + * - Uninstallations + * - User enabling and disabling + * + * Synchronization is influenced by the following preferences: + * + * - services.sync.addons.ignoreUserEnabledChanges + * - services.sync.addons.trustedSourceHostnames + * + * and also influenced by whether addons have repository caching enabled and + * whether they allow installation of addons from insecure options (both of + * which are themselves influenced by the "extensions." pref branch) + * + * See the documentation in all.js for the behavior of these prefs. + */ + +import { AddonUtils } from "resource://services-sync/addonutils.sys.mjs"; +import { AddonsReconciler } from "resource://services-sync/addonsreconciler.sys.mjs"; +import { + Store, + SyncEngine, + LegacyTracker, +} from "resource://services-sync/engines.sys.mjs"; +import { CryptoWrapper } from "resource://services-sync/record.sys.mjs"; +import { Svc, Utils } from "resource://services-sync/util.sys.mjs"; + +import { SCORE_INCREMENT_XLARGE } from "resource://services-sync/constants.sys.mjs"; +import { CollectionValidator } from "resource://services-sync/collection_validator.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + AddonManager: "resource://gre/modules/AddonManager.sys.mjs", + AddonRepository: "resource://gre/modules/addons/AddonRepository.sys.mjs", +}); + +// 7 days in milliseconds. +const PRUNE_ADDON_CHANGES_THRESHOLD = 60 * 60 * 24 * 7 * 1000; + +/** + * AddonRecord represents the state of an add-on in an application. + * + * Each add-on has its own record for each application ID it is installed + * on. + * + * The ID of add-on records is a randomly-generated GUID. It is random instead + * of deterministic so the URIs of the records cannot be guessed and so + * compromised server credentials won't result in disclosure of the specific + * add-ons present in a Sync account. + * + * The record contains the following fields: + * + * addonID + * ID of the add-on. This correlates to the "id" property on an Addon type. + * + * applicationID + * The application ID this record is associated with. + * + * enabled + * Boolean stating whether add-on is enabled or disabled by the user. + * + * source + * String indicating where an add-on is from. Currently, we only support + * the value "amo" which indicates that the add-on came from the official + * add-ons repository, addons.mozilla.org. In the future, we may support + * installing add-ons from other sources. This provides a future-compatible + * mechanism for clients to only apply records they know how to handle. + */ +function AddonRecord(collection, id) { + CryptoWrapper.call(this, collection, id); +} +AddonRecord.prototype = { + _logName: "Record.Addon", +}; +Object.setPrototypeOf(AddonRecord.prototype, CryptoWrapper.prototype); + +Utils.deferGetSet(AddonRecord, "cleartext", [ + "addonID", + "applicationID", + "enabled", + "source", +]); + +/** + * The AddonsEngine handles synchronization of add-ons between clients. + * + * The engine maintains an instance of an AddonsReconciler, which is the entity + * maintaining state for add-ons. It provides the history and tracking APIs + * that AddonManager doesn't. + * + * The engine instance overrides a handful of functions on the base class. The + * rationale for each is documented by that function. + */ +export function AddonsEngine(service) { + SyncEngine.call(this, "Addons", service); + + this._reconciler = new AddonsReconciler(this._tracker.asyncObserver); +} + +AddonsEngine.prototype = { + _storeObj: AddonsStore, + _trackerObj: AddonsTracker, + _recordObj: AddonRecord, + version: 1, + + syncPriority: 5, + + _reconciler: null, + + async initialize() { + await SyncEngine.prototype.initialize.call(this); + await this._reconciler.ensureStateLoaded(); + }, + + /** + * Override parent method to find add-ons by their public ID, not Sync GUID. + */ + async _findDupe(item) { + let id = item.addonID; + + // The reconciler should have been updated at the top of the sync, so we + // can assume it is up to date when this function is called. + let addons = this._reconciler.addons; + if (!(id in addons)) { + return null; + } + + let addon = addons[id]; + if (addon.guid != item.id) { + return addon.guid; + } + + return null; + }, + + /** + * Override getChangedIDs to pull in tracker changes plus changes from the + * reconciler log. + */ + async getChangedIDs() { + let changes = {}; + const changedIDs = await this._tracker.getChangedIDs(); + for (let [id, modified] of Object.entries(changedIDs)) { + changes[id] = modified; + } + + let lastSync = await this.getLastSync(); + let lastSyncDate = new Date(lastSync * 1000); + + // The reconciler should have been refreshed at the beginning of a sync and + // we assume this function is only called from within a sync. + let reconcilerChanges = this._reconciler.getChangesSinceDate(lastSyncDate); + let addons = this._reconciler.addons; + for (let change of reconcilerChanges) { + let changeTime = change[0]; + let id = change[2]; + + if (!(id in addons)) { + continue; + } + + // Keep newest modified time. + if (id in changes && changeTime < changes[id]) { + continue; + } + + if (!(await this.isAddonSyncable(addons[id]))) { + continue; + } + + this._log.debug("Adding changed add-on from changes log: " + id); + let addon = addons[id]; + changes[addon.guid] = changeTime.getTime() / 1000; + } + + return changes; + }, + + /** + * Override start of sync function to refresh reconciler. + * + * Many functions in this class assume the reconciler is refreshed at the + * top of a sync. If this ever changes, those functions should be revisited. + * + * Technically speaking, we don't need to refresh the reconciler on every + * sync since it is installed as an AddonManager listener. However, add-ons + * are complicated and we force a full refresh, just in case the listeners + * missed something. + */ + async _syncStartup() { + // We refresh state before calling parent because syncStartup in the parent + // looks for changed IDs, which is dependent on add-on state being up to + // date. + await this._refreshReconcilerState(); + return SyncEngine.prototype._syncStartup.call(this); + }, + + /** + * Override end of sync to perform a little housekeeping on the reconciler. + * + * We prune changes to prevent the reconciler state from growing without + * bound. Even if it grows unbounded, there would have to be many add-on + * changes (thousands) for it to slow things down significantly. This is + * highly unlikely to occur. Still, we exercise defense just in case. + */ + async _syncCleanup() { + let lastSync = await this.getLastSync(); + let ms = 1000 * lastSync - PRUNE_ADDON_CHANGES_THRESHOLD; + this._reconciler.pruneChangesBeforeDate(new Date(ms)); + return SyncEngine.prototype._syncCleanup.call(this); + }, + + /** + * Helper function to ensure reconciler is up to date. + * + * This will load the reconciler's state from the file + * system (if needed) and refresh the state of the reconciler. + */ + async _refreshReconcilerState() { + this._log.debug("Refreshing reconciler state"); + return this._reconciler.refreshGlobalState(); + }, + + // Returns a promise + isAddonSyncable(addon, ignoreRepoCheck) { + return this._store.isAddonSyncable(addon, ignoreRepoCheck); + }, +}; +Object.setPrototypeOf(AddonsEngine.prototype, SyncEngine.prototype); + +/** + * This is the primary interface between Sync and the Addons Manager. + * + * In addition to the core store APIs, we provide convenience functions to wrap + * Add-on Manager APIs with Sync-specific semantics. + */ +function AddonsStore(name, engine) { + Store.call(this, name, engine); +} +AddonsStore.prototype = { + // Define the add-on types (.type) that we support. + _syncableTypes: ["extension", "theme"], + + _extensionsPrefs: Services.prefs.getBranch("extensions."), + + get reconciler() { + return this.engine._reconciler; + }, + + /** + * Override applyIncoming to filter out records we can't handle. + */ + async applyIncoming(record) { + // The fields we look at aren't present when the record is deleted. + if (!record.deleted) { + // Ignore records not belonging to our application ID because that is the + // current policy. + if (record.applicationID != Services.appinfo.ID) { + this._log.info( + "Ignoring incoming record from other App ID: " + record.id + ); + return; + } + + // Ignore records that aren't from the official add-on repository, as that + // is our current policy. + if (record.source != "amo") { + this._log.info( + "Ignoring unknown add-on source (" + + record.source + + ")" + + " for " + + record.id + ); + return; + } + } + + // Ignore incoming records for which an existing non-syncable addon + // exists. Note that we do not insist that the addon manager already have + // metadata for this addon - it's possible our reconciler previously saw the + // addon but the addon-manager cache no longer has it - which is fine for a + // new incoming addon. + // (Note that most other cases where the addon-manager cache is invalid + // doesn't get this treatment because that cache self-repairs after some + // time - but it only re-populates addons which are currently installed.) + let existingMeta = this.reconciler.addons[record.addonID]; + if ( + existingMeta && + !(await this.isAddonSyncable(existingMeta, /* ignoreRepoCheck */ true)) + ) { + this._log.info( + "Ignoring incoming record for an existing but non-syncable addon", + record.addonID + ); + return; + } + + await Store.prototype.applyIncoming.call(this, record); + }, + + /** + * Provides core Store API to create/install an add-on from a record. + */ + async create(record) { + // This will throw if there was an error. This will get caught by the sync + // engine and the record will try to be applied later. + const results = await AddonUtils.installAddons([ + { + id: record.addonID, + syncGUID: record.id, + enabled: record.enabled, + requireSecureURI: this._extensionsPrefs.getBoolPref( + "install.requireSecureOrigin", + true + ), + }, + ]); + + if (results.skipped.includes(record.addonID)) { + this._log.info("Add-on skipped: " + record.addonID); + // Just early-return for skipped addons - we don't want to arrange to + // try again next time because the condition that caused up to skip + // will remain true for this addon forever. + return; + } + + let addon; + for (let a of results.addons) { + if (a.id == record.addonID) { + addon = a; + break; + } + } + + // This should never happen, but is present as a fail-safe. + if (!addon) { + throw new Error("Add-on not found after install: " + record.addonID); + } + + this._log.info("Add-on installed: " + record.addonID); + }, + + /** + * Provides core Store API to remove/uninstall an add-on from a record. + */ + async remove(record) { + // If this is called, the payload is empty, so we have to find by GUID. + let addon = await this.getAddonByGUID(record.id); + if (!addon) { + // We don't throw because if the add-on could not be found then we assume + // it has already been uninstalled and there is nothing for this function + // to do. + return; + } + + this._log.info("Uninstalling add-on: " + addon.id); + await AddonUtils.uninstallAddon(addon); + }, + + /** + * Provides core Store API to update an add-on from a record. + */ + async update(record) { + let addon = await this.getAddonByID(record.addonID); + + // update() is called if !this.itemExists. And, since itemExists consults + // the reconciler only, we need to take care of some corner cases. + // + // First, the reconciler could know about an add-on that was uninstalled + // and no longer present in the add-ons manager. + if (!addon) { + await this.create(record); + return; + } + + // It's also possible that the add-on is non-restartless and has pending + // install/uninstall activity. + // + // We wouldn't get here if the incoming record was for a deletion. So, + // check for pending uninstall and cancel if necessary. + if (addon.pendingOperations & lazy.AddonManager.PENDING_UNINSTALL) { + addon.cancelUninstall(); + + // We continue with processing because there could be state or ID change. + } + + await this.updateUserDisabled(addon, !record.enabled); + }, + + /** + * Provide core Store API to determine if a record exists. + */ + async itemExists(guid) { + let addon = this.reconciler.getAddonStateFromSyncGUID(guid); + + return !!addon; + }, + + /** + * Create an add-on record from its GUID. + * + * @param guid + * Add-on GUID (from extensions DB) + * @param collection + * Collection to add record to. + * + * @return AddonRecord instance + */ + async createRecord(guid, collection) { + let record = new AddonRecord(collection, guid); + record.applicationID = Services.appinfo.ID; + + let addon = this.reconciler.getAddonStateFromSyncGUID(guid); + + // If we don't know about this GUID or if it has been uninstalled, we mark + // the record as deleted. + if (!addon || !addon.installed) { + record.deleted = true; + return record; + } + + record.modified = addon.modified.getTime() / 1000; + + record.addonID = addon.id; + record.enabled = addon.enabled; + + // This needs to be dynamic when add-ons don't come from AddonRepository. + record.source = "amo"; + + return record; + }, + + /** + * Changes the id of an add-on. + * + * This implements a core API of the store. + */ + async changeItemID(oldID, newID) { + // We always update the GUID in the reconciler because it will be + // referenced later in the sync process. + let state = this.reconciler.getAddonStateFromSyncGUID(oldID); + if (state) { + state.guid = newID; + await this.reconciler.saveState(); + } + + let addon = await this.getAddonByGUID(oldID); + if (!addon) { + this._log.debug( + "Cannot change item ID (" + + oldID + + ") in Add-on " + + "Manager because old add-on not present: " + + oldID + ); + return; + } + + addon.syncGUID = newID; + }, + + /** + * Obtain the set of all syncable add-on Sync GUIDs. + * + * This implements a core Store API. + */ + async getAllIDs() { + let ids = {}; + + let addons = this.reconciler.addons; + for (let id in addons) { + let addon = addons[id]; + if (await this.isAddonSyncable(addon)) { + ids[addon.guid] = true; + } + } + + return ids; + }, + + /** + * Wipe engine data. + * + * This uninstalls all syncable addons from the application. In case of + * error, it logs the error and keeps trying with other add-ons. + */ + async wipe() { + this._log.info("Processing wipe."); + + await this.engine._refreshReconcilerState(); + + // We only wipe syncable add-ons. Wipe is a Sync feature not a security + // feature. + let ids = await this.getAllIDs(); + for (let guid in ids) { + let addon = await this.getAddonByGUID(guid); + if (!addon) { + this._log.debug( + "Ignoring add-on because it couldn't be obtained: " + guid + ); + continue; + } + + this._log.info("Uninstalling add-on as part of wipe: " + addon.id); + await Utils.catch.call(this, () => addon.uninstall())(); + } + }, + + /** ************************************************************************* + * Functions below are unique to this store and not part of the Store API * + ***************************************************************************/ + + /** + * Obtain an add-on from its public ID. + * + * @param id + * Add-on ID + * @return Addon or undefined if not found + */ + async getAddonByID(id) { + return lazy.AddonManager.getAddonByID(id); + }, + + /** + * Obtain an add-on from its Sync GUID. + * + * @param guid + * Add-on Sync GUID + * @return DBAddonInternal or null + */ + async getAddonByGUID(guid) { + return lazy.AddonManager.getAddonBySyncGUID(guid); + }, + + /** + * Determines whether an add-on is suitable for Sync. + * + * @param addon + * Addon instance + * @param ignoreRepoCheck + * Should we skip checking the Addons repository (primarially useful + * for testing and validation). + * @return Boolean indicating whether it is appropriate for Sync + */ + async isAddonSyncable(addon, ignoreRepoCheck = false) { + // Currently, we limit syncable add-ons to those that are: + // 1) In a well-defined set of types + // 2) Installed in the current profile + // 3) Not installed by a foreign entity (i.e. installed by the app) + // since they act like global extensions. + // 4) Is not a hotfix. + // 5) The addons XPIProvider doesn't veto it (i.e not being installed in + // the profile directory, or any other reasons it says the addon can't + // be synced) + // 6) Are installed from AMO + + // We could represent the test as a complex boolean expression. We go the + // verbose route so the failure reason is logged. + if (!addon) { + this._log.debug("Null object passed to isAddonSyncable."); + return false; + } + + if (!this._syncableTypes.includes(addon.type)) { + this._log.debug( + addon.id + " not syncable: type not in allowed list: " + addon.type + ); + return false; + } + + if (!(addon.scope & lazy.AddonManager.SCOPE_PROFILE)) { + this._log.debug(addon.id + " not syncable: not installed in profile."); + return false; + } + + // If the addon manager says it's not syncable, we skip it. + if (!addon.isSyncable) { + this._log.debug(addon.id + " not syncable: vetoed by the addon manager."); + return false; + } + + // This may be too aggressive. If an add-on is downloaded from AMO and + // manually placed in the profile directory, foreignInstall will be set. + // Arguably, that add-on should be syncable. + // TODO Address the edge case and come up with more robust heuristics. + if (addon.foreignInstall) { + this._log.debug(addon.id + " not syncable: is foreign install."); + return false; + } + + // If the AddonRepository's cache isn't enabled (which it typically isn't + // in tests), getCachedAddonByID always returns null - so skip the check + // in that case. We also provide a way to specifically opt-out of the check + // even if the cache is enabled, which is used by the validators. + if (ignoreRepoCheck || !lazy.AddonRepository.cacheEnabled) { + return true; + } + + let result = await new Promise(res => { + lazy.AddonRepository.getCachedAddonByID(addon.id, res); + }); + + if (!result) { + this._log.debug( + addon.id + " not syncable: add-on not found in add-on repository." + ); + return false; + } + + return this.isSourceURITrusted(result.sourceURI); + }, + + /** + * Determine whether an add-on's sourceURI field is trusted and the add-on + * can be installed. + * + * This function should only ever be called from isAddonSyncable(). It is + * exposed as a separate function to make testing easier. + * + * @param uri + * nsIURI instance to validate + * @return bool + */ + isSourceURITrusted: function isSourceURITrusted(uri) { + // For security reasons, we currently limit synced add-ons to those + // installed from trusted hostname(s). We additionally require TLS with + // the add-ons site to help prevent forgeries. + let trustedHostnames = Svc.PrefBranch.getStringPref( + "addons.trustedSourceHostnames", + "" + ).split(","); + + if (!uri) { + this._log.debug("Undefined argument to isSourceURITrusted()."); + return false; + } + + // Scheme is validated before the hostname because uri.host may not be + // populated for certain schemes. It appears to always be populated for + // https, so we avoid the potential NS_ERROR_FAILURE on field access. + if (uri.scheme != "https") { + this._log.debug("Source URI not HTTPS: " + uri.spec); + return false; + } + + if (!trustedHostnames.includes(uri.host)) { + this._log.debug("Source hostname not trusted: " + uri.host); + return false; + } + + return true; + }, + + /** + * Update the userDisabled flag on an add-on. + * + * This will enable or disable an add-on. It has no return value and does + * not catch or handle exceptions thrown by the addon manager. If no action + * is needed it will return immediately. + * + * @param addon + * Addon instance to manipulate. + * @param value + * Boolean to which to set userDisabled on the passed Addon. + */ + async updateUserDisabled(addon, value) { + if (addon.userDisabled == value) { + return; + } + + // A pref allows changes to the enabled flag to be ignored. + if (Svc.PrefBranch.getBoolPref("addons.ignoreUserEnabledChanges", false)) { + this._log.info( + "Ignoring enabled state change due to preference: " + addon.id + ); + return; + } + + AddonUtils.updateUserDisabled(addon, value); + // updating this flag doesn't send a notification for appDisabled addons, + // meaning the reconciler will not update its state and may resync the + // addon - so explicitly rectify the state (bug 1366994) + if (addon.appDisabled) { + await this.reconciler.rectifyStateFromAddon(addon); + } + }, +}; + +Object.setPrototypeOf(AddonsStore.prototype, Store.prototype); + +/** + * The add-ons tracker keeps track of real-time changes to add-ons. + * + * It hooks up to the reconciler and receives notifications directly from it. + */ +function AddonsTracker(name, engine) { + LegacyTracker.call(this, name, engine); +} +AddonsTracker.prototype = { + get reconciler() { + return this.engine._reconciler; + }, + + get store() { + return this.engine._store; + }, + + /** + * This callback is executed whenever the AddonsReconciler sends out a change + * notification. See AddonsReconciler.addChangeListener(). + */ + async changeListener(date, change, addon) { + this._log.debug("changeListener invoked: " + change + " " + addon.id); + // Ignore changes that occur during sync. + if (this.ignoreAll) { + return; + } + + if (!(await this.store.isAddonSyncable(addon))) { + this._log.debug( + "Ignoring change because add-on isn't syncable: " + addon.id + ); + return; + } + + const added = await this.addChangedID(addon.guid, date.getTime() / 1000); + if (added) { + this.score += SCORE_INCREMENT_XLARGE; + } + }, + + onStart() { + this.reconciler.startListening(); + this.reconciler.addChangeListener(this); + }, + + onStop() { + this.reconciler.removeChangeListener(this); + this.reconciler.stopListening(); + }, +}; + +Object.setPrototypeOf(AddonsTracker.prototype, LegacyTracker.prototype); + +export class AddonValidator extends CollectionValidator { + constructor(engine = null) { + super("addons", "id", ["addonID", "enabled", "applicationID", "source"]); + this.engine = engine; + } + + async getClientItems() { + return lazy.AddonManager.getAllAddons(); + } + + normalizeClientItem(item) { + let enabled = !item.userDisabled; + if (item.pendingOperations & lazy.AddonManager.PENDING_ENABLE) { + enabled = true; + } else if (item.pendingOperations & lazy.AddonManager.PENDING_DISABLE) { + enabled = false; + } + return { + enabled, + id: item.syncGUID, + addonID: item.id, + applicationID: Services.appinfo.ID, + source: "amo", // check item.foreignInstall? + original: item, + }; + } + + async normalizeServerItem(item) { + let guid = await this.engine._findDupe(item); + if (guid) { + item.id = guid; + } + return item; + } + + clientUnderstands(item) { + return item.applicationID === Services.appinfo.ID; + } + + async syncedByClient(item) { + return ( + !item.original.hidden && + !item.original.isSystem && + !( + item.original.pendingOperations & lazy.AddonManager.PENDING_UNINSTALL + ) && + // No need to await the returned promise explicitely: + // |expr1 && expr2| evaluates to expr2 if expr1 is true. + this.engine.isAddonSyncable(item.original, true) + ); + } +} |